Background

This Briefing Note (BN) describes the human vestibular system and the illusions it can create in a pilot. It is intended to help flight crew avoid the traps associated with vestibular illusions and to increase flight safety through better awareness of their causes.

Introduction

Included in this BN is an overview of:

• How the vestibular system works
• Major influences on the vestibular system:
  • perception of motion and orientation
  • gaze stabilization
  • postural/balance systems
• Spatial disorientation related to the vestibular system
• Motion sickness
• Best practices on how to:
  • recognize when illusions are occurring
  • know which sources of information to trust (i.e., instruments versus sensations)
  • take appropriate and safe action

Data

It is not possible to quantify the role of vestibular illusions in accidents and incidents. However, the types of accidents and incidents that can result from vestibular illusions are known and include: